title: Physical fighting among school-going Portuguese adolescents: social and behavioural correlates.
abstract: OBJECTIVE
  The purpose of this study was to estimate the frequency and to assess the determinants of physical fighting among Portuguese school-going adolescents.
  
  
  METHODS
  A cross-sectional evaluation of urban adolescents born in 1990 and enrolled in public and private schools of Porto was performed in 2007. We identified 3161 17-year-old eligible adolescents and 73.3% accepted to participate. Information was collected using a self-administered questionnaire assessing socio-demographic, behavioural, family and health-related characteristics. The magnitude of the associations between those characteristics and physical fighting was estimated using logistic regression.
  
  
  RESULTS
  Overall, 33.8% of adolescents (48.6% of boys and 20.1% of girls; p < 0.001) engaged in a physical fight during the previous 12 months. The school premises were the most frequently reported setting where fights occurred (girls--41.2% and boys--46.7%, p = 0.179). After adjustment, and in both genders, we found statistically significant associations between physical fighting and grade retention, smoking, drinking and age at first sexual intercourse.
  
  
  CONCLUSIONS
  Physical fighting among school-going adolescents is frequent, tends to occur at school premises and to cluster with other well recognized adverse health behaviours.
authors.affiliation: Department of Hygiene and Epidemiology, University of Porto Medical School, Porto, Portugal; Institute of Public Health-University of Porto, Porto, Portugal. silfraga@med.up.pt
authors.forename: S
authors.initials: S
authors.lastname: Fraga
authors.forename: E
authors.initials: E
authors.lastname: Ramos
authors.forename: S
authors.initials: S
authors.lastname: Dias
authors.forename: H
authors.initials: H
authors.lastname: Barros
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D011174:Portugal; D012919:Social Behavior; D014754:Violence / Q000706:statistics & numerical data